How would you calculate cost of goods sold? What items make upcost of goods sold

How would you calculate cost of goods sold? What items make upcost of goods sold? How does beginning and ending inventory affectcost of goods sold? What are the journal entries a merchandisingorganization would use to record the purchase and subsequent saleof merchandise? How would these transactions differ with a periodicversus a perpetual inventory system? Why are perpetual inventorysystems so much more popular today than back in the early 1960s andearlier? Why would a company employing a perpetual inventory systemstill take a physical inventory periodically?